State of WASM/WASI support in Net 9

[jogibear9988]

I've a C# Library I want to consume from a Javascript App (no Blazor).
I now tried to find, how to compile to WASM/WASI with Net 9, but I only find outdated Tutorials wich do not work.

Whats the state of support? Are the samples?

found:
https://devblogs.microsoft.com/dotnet/use-net-7-from-any-javascript-app-in-net-7/
https://github.com/dotnet/dotnet-wasi-sdk
https://devblogs.microsoft.com/dotnet/extending-web-assembly-to-the-cloud/

but everything is old and does not seem to work.

[maraf]

@jogibear9988 Thank you reaching out!

There is a tutorial https://learn.microsoft.com/en-us/aspnet/core/client-side/dotnet-interop?view=aspnetcore-9.0.
The key starting point is to install wasm-experimental workload and then you can use wasmbrowser template.

There is one app in the runtime repository then we use for testing https://github.com/dotnet/runtime/tree/main/src/mono/wasm/testassets/WasmBasicTestApp/App. You can try to find others on github then are the same template (SDK in fact) https://github.com/search?q=Sdk%3D%22Microsoft.NET.Sdk.WebAssembly%22&type=code.

Let us know if you more questions.

[jogibear9988]

I try to compile my project:

        <Project Sdk="Microsoft.NET.Sdk">
        
          <PropertyGroup>
            <OutputType>Library</OutputType>
            <TargetFramework>net9.0</TargetFramework>
            <RuntimeIdentifier>browser-wasm</RuntimeIdentifier>
            <ImplicitUsings>enable</ImplicitUsings>
            <Nullable>enable</Nullable>
            <RollForward>LatestMajor</RollForward>
            <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
          </PropertyGroup>
        
          <ItemGroup>
            <ProjectReference Include="..\TiaFileFormat\TiaFileFormat.csproj" />
          </ItemGroup>
        
        </Project>

I always get this error:

          2>C:\Program Files\dotnet\sdk\9.0.200\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.Sdk.ImportWorkloads.targets(38,5): error NETSDK1147: To build this project, the following workloads must be installed: wasm-tools
          2>C:\Program Files\dotnet\sdk\9.0.200\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.Sdk.ImportWorkloads.targets(38,5): error NETSDK1147: To install these workloads, run the following command: dotnet workload restore

but the workload is installed:

[maraf]

What does dotnet workload list print for you?

Also I would encourage you to migrate to Microsoft.NET.Sdk.WebAssembly (see the wasmbrowser template in .NET9+)

[jogibear9988]

After changeing Sdk Type to Microsoft.NET.Sdk.WebAssembly it compiles...
Now I need to check WASM calls... I'll report back